Checking ground wire

Connect multimeter as follows to measure voltage:

Fig 1: Identifying Camshaft Position Sensor Harness Connector Terminals

Courtesy of AUDI OF AMERICA, INC.

CONNECTOR TERMINAL 3 VOLTAGE REFERENCE (CMP SENSOR)

Connector terminal	Measure to
3	Battery positive

Repair any open/short circuit as necessary.
If the specified values are all achieved and the LED test light does not flash (measured between terminals 1 and 2 with starter connector attached),
Install a new CMP sensor.
If the specified values are not obtained: